Polyol polymers, methods of preparing such polymers, and coating compositions containing the same

ABSTRACT

A polyol polymer is obtained from reactants including: a) a non-aromatic epoxy functional compound that includes at least 30 weight % of the total solids weight of the reactants; and b) an aromatic mono-carboxylic acid functional compound, or anhydride thereof, that is substantially free of non-aromatic ethyl enic unsaturation. The polyol polymer has ester linkages and hydroxyl functional groups, Further, if the reactants further include an aromatic polycarboxylic acid, the aromatic polycarboxylic acid makes up less than 15 weight % of the total solids weight of the reactants. A coating composition is also prepared with the polyol polymer.

FIELD OF THE INVENTION

The present invention relates to polyol polymers, methods of preparingthe polymers, coating compositions containing the same, coatings formedfrom the coating compositions, and substrates at least partially coatedwith such coatings.

BACKGROUND OF THE INVENTION

Metallic substrates and other substrates having metallic portions aresusceptible to corrosion, especially when exposed to certainenvironmental conditions. To prevent or reduce the corrosion of suchsubstrates, a coating that inhibits corrosion of these substrates istypically applied over the surface. These coatings can be applieddirectly over the substrate as a single coating layer, or additionalcoating layers can be applied over the corrosion inhibiting coatinglayer to provide other properties including color, abrasion resistance,and chemical resistance. While coatings have been developed to reducecorrosion of metallic containing substrates, it is desirable to provideimproved coatings that more effectively reduce or prevent corrosion andwhich also provide other desirable properties such as good appearance.

SUMMARY OF THE INVENTION

The present invention relates to a polyol polymer obtained fromreactants comprising: a) a non-aromatic epoxy functional compound thatcomprises at least 30 weight % of the total solids weight of thereactants; and b) an aromatic mono-carboxylic acid functional compound,or anhydride thereof, that is substantially free of non-aromaticethylenic unsaturation. The polyol polymer comprises ester linkages andhydroxyl functional groups. Further, if the reactants further comprisean aromatic polycarboxylic acid, the aromatic polycarboxylic acidcomprises less than 15 weight % of the total solids weight of thereactants.

The present invention further includes a coating composition comprisingthe previously described polymer and a crosslinker reactive with thepolymer.

The present invention also includes a method of forming a polyolpolymer. The method includes reacting reactants comprising: a) anon-aromatic epoxy functional compound that comprises at least 30 weight% of the total solids weight of the reactants; and b) an aromaticmono-carboxylic acid functional compound, or anhydride thereof, that issubstantially free of non-aromatic ethylenic unsaturation. The polyolpolymer comprises ester linkages and hydroxyl functional groups.Further, if the reactants further comprise an aromatic polycarboxylicacid, the aromatic polycarboxylic acid comprises less than 15 weight %of the total solids weight of the reactants.

DESCRIPTION OF THE INVENTION

For purposes of the following detailed description, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary.Moreover, other than in any operating examples, or where otherwiseindicated, all numbers expressing, for example, quantities ofingredients used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

In this application, the use of the singular includes the plural andplural encompasses singular, unless specifically stated otherwise. Inaddition, in this application, the use of “or” means “and/or” unlessspecifically stated otherwise, even though “and/or” may be explicitlyused in certain instances. Further, in this application, the use of “a”or “an” means “at least one” unless specifically stated otherwise. Forexample, “a” polymer, “a” coating composition, “a” crosslinker, and thelike refer to one or more of any of these items.

As indicated, the polymer of the present invention comprises a polyolpolymer obtained from reactants comprising at least a non-aromatic epoxyfunctional compound and an aromatic mono-carboxylic acid functionalcompound which is substantially free of non-aromatic ethylenicunsaturation.

As used herein, a “polyol polymer” refers to a polymer having two ormore, such as three or more, hydroxyl functional groups. The term“polymer” refers to oligomers and homopolymers (e.g., prepared from asingle monomer species), copolymers (e.g., prepared from at least twodifferent monomer species), terpolymers (e.g., prepared from at leastthree different monomer species) and graft polymers. The term “resin” isused interchangeably with “polymer.”

A “non-aromatic epoxy functional compound” refers to a linear, branched,or cyclic compound having epoxy functional groups and which is free ofaromatic groups. As used herein, the term “aromatic” refers to aconjugated cyclic hydrocarbon structure with a stability (due todelocalization) that is significantly greater than that of ahypothetical localized structure. Further, the term “linear” refers to acompound having a straight chain, the term “branched” refers to acompound having a chain with a hydrogen replaced by a substituent suchas an alkyl group that branches or extends out from a straight chain,and the term “cyclic” refers to a closed ring structure. Thus, the epoxyfunctional compound is an aliphatic compound, i.e. a non-aromaticlinear, branched, or cyclic structure that contains saturated carbonbonds.

Non-limiting examples of suitable non-aromatic epoxy functionalcompounds include a cycloaliphatic diglycidyl ether, a cycloaliphaticdiglycidyl ester, a cycloaliphatic epoxide, or a combination thereof. A“cycloaliphatic diglycidyl ether” refers to a non-aromatic cycliccompound comprising one or more ether groups and at least two epoxyfunctional groups, such as for example hydrogenated bisphenol A epoxide.A “cycloaliphatic diglycidyl ester” refers to a non-aromatic cycliccompound comprising one or more esters groups and at least two epoxyfunctional groups, such as for example 1,2-cyclohexanedicarboxylic acid,1,2-bis(2-oxiranylmethyl) ester. A “cycloaliphatic epoxide” refers to anon-aromatic cyclic compound comprising one or more epoxy functionalgroups and which does not include glycidyl ester or glycidyl ethergroups, such as for example3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate,bis((3,4-epoxycyclohexyl)methyl)adipate, or a combination thereof.

As indicated, the non-aromatic epoxy functional compound can be selectedfrom compounds prepared from a hydrogenated bisphenol polyepoxide or apolyepoxide derived from a hydrogenated bisphenol compound. For example,the non-aromatic epoxy functional compound can comprise a cycloaliphaticdiglycidyl ether formed from a hydrogenated bisphenol polyepoxide or apolyepoxide derived from a hydrogenated bisphenol compound.

The non-aromatic epoxy functional compound can also comprise additionalfunctional groups. For example, the non-aromatic epoxy functionalcompound can also comprise ester groups, ether groups, nitro groups,nitrile groups, keto functional groups (also referred to as ketonefunctional groups), aldo functional groups (also referred to as aldehydefunctional groups), amine groups, hydroxyl groups, thiol groups,carbamate groups, amide groups, urea groups, isocyanate groups(including blocked isocyanate groups), ethylenically unsaturated groups,and combinations thereof Alternatively, the non-aromatic epoxyfunctional compound can also be free of (i.e., does not contain) any oneof the previously described additional functional groups.

As used herein, “ethylenically unsaturated” refers to a group having atleast one carbon-carbon double bond. Non-limiting examples ofethylenically unsaturated groups include, but are not limited to,(meth)acrylate groups, vinyl groups, other alkenyl groups, andcombinations thereof. As used herein, the term “(meth)acrylate” refersto both the methacrylate and the acrylate.

The non-aromatic epoxy functional compound can comprise at least 30weight %, at least 40 weight %, at least 50 weight %, or at least 60weight %, based on the total solids weight of the reactants used to formthe polyol polymer. The non-aromatic epoxy functional compound cancomprise up to 90 weight %, up to 80 weight %, up to 70 weight %, or upto 65 weight %, based on the total solids weight of the reactants usedto form the polyol polymer. The non-aromatic epoxy functional compoundcan also comprise an amount within a range, such as for example, of from30 weight % to 90 weight %, or from 40 weight % to 80 weight %, or from50 weight % to 70 weight %, or from 60 weight % to 70 weight %, based onthe total solids weight of the reactants used to form the polyolpolymer.

As previously described, the polyol polymer is also prepared with anaromatic mono-carboxylic acid functional compound that is substantiallyfree of non-aromatic ethylenic unsaturation. As used herein, an“aromatic mono-carboxylic acid functional compound” refers to a compoundthat includes a cyclically conjugated hydrocarbon with a stability thatis significantly greater than that of a hypothetical localized structureand which also includes a single carboxylic acid group or the ester oranhydride of the acid.

As indicated, the aromatic mono-carboxylic acid functional compound issubstantially free of non-aromatic ethylenic unsaturation. The aromaticmono-carboxylic acid functional compound can also be essentially free orcompletely free of non-aromatic ethylenic unsaturation. The term“non-aromatic ethylenic unsaturation” refers to carbon-carbon doublebonds that do not form a part of a cyclically conjugated hydrocarbonaromatic group. Further, the terms “substantially free of non-aromaticethylenic unsaturation” means that the mixture of reactants containsless than 1000 parts per million (ppm) of compounds containingnon-aromatic ethylenic unsaturation, “essentially free of non-aromaticethylenic unsaturation” means that the mixture of reactants containsless than 100 ppm of compounds containing non-aromatic ethylenicunsaturation, and “completely free of non-aromatic ethylenicunsaturation” means that the mixture of reactants contains less than 20parts per billion (ppb) of compounds containing non-aromatic ethylenicunsaturation.

The aromatic mono-carboxylic acid functional compound can also compriseadditional functional groups. For example, the aromatic mono-carboxylicacid functional compound can also comprise any of the additionalfunctional groups previously described provided that the aromaticmono-carboxylic acid functional compound is substantially free,essentially free, or completely free of non-aromatic ethylenicunsaturation. Alternatively, the aromatic mono-carboxylic acidfunctional compound is free of (i.e., does not contain) any of thepreviously described additional functional groups.

Non-limiting examples of aromatic monoacids that can be used to preparethe polymer include benzoic acid, 4-tert-butylbenzoic acid,hydroxybenzoic acids such as 4-hydroxybenzoic acid, salicylic acid,naphthoic acids, amino benzoic acids such as 4-aminobenzoic acid,nitrobenzoic acids such as 4-nitrobenzoic acid, 3,5-dinitrobenzoic acid,phenylpropanoic acid, mandelic acid, 3-benzoylpropanoic acid,anthranilic acid, nicotinic acid, picolinic acid, anhydrides of suchacids, and combinations thereof.

The aromatic mono-carboxylic acid functional compound can comprise atleast 10 weight %, at least 15 weight %, at least 20 weight %, at least25 weight %, or at least 30 weight %, based on the total solids weightof the reactants used to form the polyol polymer. The aromaticmono-carboxylic acid functional compound can comprise up to 45 weight %,up to 40 weight %, or up to 35 weight %, based on the total solidsweight of the reactants used to form the polyol polymer. The aromaticmono-carboxylic acid functional compound can also comprise an amountwithin a range, such as for example, of from 10 weight % to 45 weight %,or from 15 weight % to 40 weight %, or from 15 weight % to 35 weight %,or from 20 weight % to 35 weight %, based on the total solids weight ofthe reactants used to form the polyol polymer.

The reactants that form the polyol polymer may further comprise anaromatic polycarboxylic acid provided that the aromatic polycarboxylicacid is less than 15 weight %, less than 10 weight %, less than 5 weight% or less than 1 weight %, based on the total solids weight of thereactants used to form the polyol polymer. The reactants that form thepolyol polymer can also be substantially free, essentially free, orcompletely free of an aromatic polycarboxylic acid. That is, thereactants that form the polyol polymer may be substantially free ofaromatic polycarboxylic acids in which the mixture of reactants containless than 1000 ppm of aromatic polycarboxylic acids, essentially free ofaromatic polycarboxylic acids in which the mixture of reactants containless than 100 ppm of aromatic polycarboxylic acids, and completely freeof aromatic polycarboxylic acids in which the mixture of reactantscontain less than 20 ppb of aromatic polycarboxylic acids.

As used herein, an “aromatic polycarboxylic acid” refers to a compoundthat includes a cyclically conjugated hydrocarbon with a stability thatis significantly greater than that of a hypothetical localized structureand which also includes a two or more carboxylic acid groups or theanhydride of the acid. Non-limiting examples of aromatic polycarboxylicacids include terephthalic acid, isophthalic acid, orthophthalic acid,trimellitic acid, anhydrides of such acids, and combinations thereof.

The aromatic polycarboxylic acid can also comprise additional functionalgroups. For example, the aromatic polycarboxylic acid can also compriseany of the additional functional groups previously described.Alternatively, the aromatic polycarboxylic acid is free of (i.e., doesnot contain) any of the previously described additional functionalgroups.

The polyol polymer can also be prepared with additional reactants. Forexample, the reactants that form the polyol polymer may further comprisenon-aromatic carboxylic acids such as non-aromatic mono-carboxylicacids, non-aromatic polycarboxylic acids, anhydrides of such acids, andcombinations thereof.

As used herein, a “non-aromatic mono-carboxylic acid” refers to astraight, branched, or cyclic structure that contains saturated carbonbonds, a single carboxylic acid, or anhydride thereof, and which is freeof aromatic groups. Further, a “non-aromatic polycarboxylic acid” refersto a straight, branched, or cyclic structure that contains saturatedcarbon bonds, two or more carboxylic acids, or anhydrides thereof, andwhich is free of aromatic groups.

The non-aromatic mono-carboxylic acid and/or non-aromatic polycarboxylicacid can also comprise additional functional groups. For example, thenon-aromatic mono-carboxylic acid and/or non-aromatic polycarboxylicacid can also comprise any of the additional functional groupspreviously described. For example, the non-aromatic mono-carboxylic acidand/or non-aromatic polycarboxylic acid can also comprise hydroxylfunctional groups. Alternatively, the non-aromatic mono-carboxylic acidand/or non-aromatic polycarboxylic acid are free of (i.e., does notcontain) any of the previously described additional functional groups.

Non-limiting examples of non-aromatic mono-carboxylic acids includecycloaliphatic carboxylic acids such as cyclohexane carboxylic acid,C₁-C₁₈ linear or branched carboxylic acids such as acetic acid,propanoic acid, butanoic acid, hexanoic acid, heptanoic acid, andoctanoic acid, anhydrides of such acids, and combinations thereof

Non-limiting examples of non-aromatic polycarboxylic acids include1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid,decahydronaphthalene dicarboxylic acid, 1,3-cyclopentanedicarboxylicacid, 1,1-cyclopropanedicarboxylic acid, hexahydrophthalic acid,succinic acid, acipic acid, azelaic acid, citric acid, anhydrides ofsuch acids, and combinations thereof.

When used to form the polyol polymer, the non-aromatic mono-carboxylicacid and/or non-aromatic polycarboxylic acid can each independentlycomprise at least 1 weight %, at least 3 weight %, or at least 5 weight%, based on the total solids weight of the reactants used to form thepolyol polymer. The non-aromatic mono-carboxylic acid and/ornon-aromatic polycarboxylic acid can each independently comprise up to25 weight %, up to 15 weight %, or up to 10 weight %, based on the totalsolids weight of the reactants used to form the polyol polymer. Thenon-aromatic mono-carboxylic acid and/or non-aromatic polycarboxylicacid can also each independently comprise an amount within a range, suchas for example, of from 1 weight % to 25 weight %, or from 3 weight % to15 weight %, or from 5 weight % to 15 weight %, or from 5 weight % to 10weight %, based on the total solids weight of the reactants used to formthe polyol polymer.

Other additional reactants that can be used to form the polyol polymerinclude intramolecular cyclic esters. An “intramolecular cyclic ester”refers to a cyclic ring in which an ester linkage is part of the ringstructure. The intramolecular cyclic ester can comprise, for example, acyclic mono-ester or di-ester. Non-limiting examples of intramolecularcyclic esters include a lactone, lactide, glycolide, or a combinationthereof. A “lactone” refers to a cyclic ester having a ring structurewith two or more carbon atoms and a single oxygen atom with a ketonegroup in one of the carbons adjacent to the other oxygen. A “lactide”refers to a cyclic di-ester obtained from two or more molecules oflactic acid, and a “glycolide” refers to a cyclic ester obtained bydehydration of two water molecules from two glycolic acid molecules.Non-limiting examples of suitable lactones include ε-caprolactone,β-propiolactone, γ-butyrolactone, δ-valerolactone, and combinationsthereof. Non-limiting examples of suitable lactides include L-lactide,D-lactide, DL-lactide, and combinations thereof.

When used to form the polyol polymer, the intramolecular cyclic estercan comprise at least 1 weight %, at least 3 weight %, or at least 5weight %, based on the total solids weight of the reactants used to formthe polyol polymer. The intramolecular cyclic ester can comprise up to50 weight %, or up to 40 weight %, or up to 30 weight %, or 20 weight %,or up to 15 weight %, or up to 10 weight %, based on the total solidsweight of the reactants used to form the polyol polymer. Theintramolecular cyclic ester can comprise an amount within a range, suchas for example, of from 1 weight % to 50 weight %, or from 3 weight % to40 weight %, or from 5 weight % to 30 weight %, or from 5 weight % to 20weight %, based on the total solids weight of the reactants used to formthe polyol polymer.

The present invention is also directed to a method of preparing thepreviously described polyol polymer. The method can comprise mixing andreacting all the desired reactants at the same time to form the polyolpolymer. Alternatively, the reactants can be reacted in a stepwisemanner by first mixing and reacting only a portion of the reactants toform a preliminary reaction product and then mixing and reacting theremaining reactants with the preliminary reaction product to form thepolyol polymer. For example, the polyol polymer can be prepared by firstreacting reactants comprising the non-aromatic epoxy functional compoundand the aromatic mono-carboxylic acid functional compound which issubstantially free of non-aromatic ethylenic unsaturation to form apreliminary reaction product, and then reacting the preliminary reactionproduct with additional reactants such as an intramolecular cyclicester.

Various types of reaction aids can also be added to the reaction mixtureincluding, but not limited to, catalysts. Non-limiting examples ofcatalysts include triphenylphosphine, ethyltriphenylphosphonium iodide,butyl stannoic acid, and combinations thereof

The reactants and other optional components can also be combined andreacted in a liquid medium such as a non-aqueous liquid medium. As usedherein, the term “non-aqueous” refers to a liquid medium comprising lessthan 50 weight % water, based on the total weight of the liquid medium.In accordance with the present invention, such non-aqueous liquidmediums can comprise less than 40 weight % water, or less than 30 weight% water, or less than 20 weight % water, or less than 10 weight % water,or less than 5% water, based on the total weight of the liquid medium.The solvents that make up more than 50 weight % of the liquid mediuminclude organic solvents. Non-limiting examples of suitable organicsolvents include polar organic solvents e.g. protic organic solventssuch as glycols, glycol ether alcohols, alcohols; and ketones, glycoldiethers, esters, and diesters. Other non-limiting examples of organicsolvents include aromatic and aliphatic hydrocarbons.

The resulting polyol polymer of the present invention comprises esterlinkages and hydroxyl functional groups. The polyol polymer can alsocomprise other linkages and functional groups. For example, the polyolpolymer can also comprise ether linkages and/or any of the additionalfunctional groups previously described such as epoxy functional groupsand/or carboxylic acid functional groups.

The polyol polymer prepared from the reactants described above can havea hydroxyl value of at least 50 mg KOH/g, at least 75 mg KOH/g, or atleast 100 mg KOH/g. The polyol polymer prepared from the reactantsdescribed above can also have a hydroxyl value of up to 300 mg KOH/g, atleast 250 mg KOH/g, or at least 200 mg KOH/g. The polyol polymer productprepared from the reactants described above can further have a hydroxylvalue within a range of from 50 to 300 mg KOH/g, or from 75 to 250 mgKOH/g, or from 100 to 200 mg KOH/g.

The hydroxyl value is determined by esterification of the sample withexcess acetic anhydride. The excess acetic anhydride is converted toacetic acid by hydrolysis and titrated potentiometrically with standardpotassium hydroxide. The volume difference of titrate potassiumhydroxide between a blank (no reaction) and the sample corresponds tothe acid content of the sample, from which the hydroxyl number iscalculated as the number of milligrams of potassium hydroxide needed toneutralize the acid in one gram of the sample. The hydrolyzing solutionused in the determination is a mixture of dimethylformamide, pyridine,and distilled water, and the acetylating reagent is a mixture of aceticanhydride and dichloroethane with p-toluene sulphonic acid as thecatalyst.

The polyol polymer prepared from the reactants can comprise a weightaverage molecular weight of less than 10,000 g/mol, less than 8,000g/mol, less than 6,000 g/mol, or less than 5,000 g/mol. The weightaverage molecular weight is determined by Gel Permeation Chromatographyusing a Waters 2695 separation module with a Waters 410 differentialrefractometer (RI detector) and polystyrene standards in whichtetrahydrofuran (THF) is used as the eluent at a flow rate of 1 ml min⁻¹and two PL Gel Mixed C columns used for separation.

The polyol polymer prepared from the reactants can have a polydispersityindex (PDI) of at least 1.05, at least 1.2, or at least 1.3. The polyolpolymer prepared from the reactants can have a PDI of up to 3.50, up to2.5, or up to 1.8. The polyol polymer prepared from the reactants canalso have a PDI within a range such as, for example, of from 1.05 to3.50, or from 1.2 to 2.5, or from 1.3 to 1.8. The PDI values represent aratio of the weight average molecular weight (Mw) to the number averagemolecular weight (Mn) of the polymer (i.e., Mw/Mn). The weight averagemolecular weight and polydispersity index and the number averagemolecular weight are determined by gel permeation chromatography aspreviously described with respect to the weight average molecularweight.

The polyol polymer prepared from the reactants can also comprise aparticular equivalent ratio of functional groups. For instance, when thepolyol polymer comprises epoxy and carboxylic acid functional groups,the equivalent ratio of epoxy functional groups to acid functionalgroups is from 0.95:5.0, or from 1.10 to 2.0, or from 1.15 to 1.5.

The present invention is also directed to a coating composition thatcomprises the polyol polymer and a crosslinker(s) reactive with one ormore functional groups of the polyol polymer. It is appreciated that thepolyol polymer in the coating composition acts as a film-forming resin.As used herein, a “film-forming resin” refers to a self-supportingcontinuous film on at least a horizontal surface of a substrate uponremoval of any diluents or carriers present in the composition or uponcuring. The terms “curable”, “cure”, and the like, as used in connectionwith a coating composition, means that at least a portion of thecomponents that make up the coating composition are polymerizable and/orcrosslinkable. The coating composition of the present invention can becured at ambient conditions, with heat, or with other means such asactinic radiation. The term “actinic radiation” refers toelectromagnetic radiation that can initiate chemical reactions. Actinicradiation includes, but is not limited to, visible light, ultraviolet(UV) light, X-ray, and gamma radiation. Further, “ambient conditions”refers to the conditions of the surrounding environment (e.g., thetemperature, humidity, and pressure of the room or outdoor environmentin which the substrate is located such as, for example, at a temperatureof 23° C. and at a relative humidity in the air of 35% to 75%).

The coating composition can comprise one or more of the polyol polymerspreviously described. For instance, the coating composition can compriseat least one polyol polymer that is not prepared with an intramolecularcyclic ester and at least one polyol polymer that is prepared with anintramolecular cyclic ester.

The polyol polymer can comprise at least 15 weight %, at least 20 weight%, at least 25 weight %, or at least 30 weight %, based on the totalweight of the coating composition. The polyol polymer can comprise up to80 weight %, up to 70 weight %, up to 60 weight %, or up to 50 weight %,based on the total weight of the coating composition. The polyol polymercan comprise an amount within a range such as, for example, from 15 to80 weight %, or from 20 to 70 weight %, or from 25 to 60 weight %, orfrom 30 to 50 weight %, based on the total weight of the coatingcomposition.

As previously described, the coating composition comprises acrosslinker(s) reactive with one or more functional groups of the polyolpolymer. As used herein, the term “crosslinker” refers to a moleculecomprising two or more functional groups that are reactive with otherfunctional groups and which is capable of linking two or more monomersor polymer molecules through chemical bonds such as during a curingprocess. Thus, the coating composition comprises a crosslinker havingfunctional groups that are reactive with at least some of the functionalgroups on the polyol polymer.

Non-limiting examples of crosslinkers include carbodiimides,polyhydrazides, aziridines, epoxy resins, alkylated carbamate resins,(meth)acrylates, isocyanates, blocked isocyanates, polyacids,polyamines, polyamides, aminoplasts such as melamine-formaldehyderesins, hydroxyalkyl ureas, hydroxyalkyl amides, and any combinationthereof. For instance, the crosslinker can comprise a polyisocyanate,aminoplast, or a combination thereof that is reactive with at least thehydroxyl functional groups on the polyol polymer.

It is appreciated that the coating composition can include a single typeor multiple types of crosslinkers. For instance, the coating compositioncan comprise at least two different types of crosslinkers that arereactive with the same functional groups or different functional groupson the polyol polymer. The coating composition can also comprise atleast two different types of crosslinkers that are reactive withdifferent types of polyol polymers when used as previously described.

The coating composition can also comprise additional components. Forexample, the coating composition can also comprise additionalfilm-forming resins. The additional resins can include any of a varietyof thermoplastic and/or thermosetting resins known in the art. As usedherein, the term “thermosetting” refers to resins that “set”irreversibly upon curing or crosslinking, wherein the polymer chains arejoined together by covalent bonds. This property is usually associatedwith a cross-linking reaction often induced, for example, by heat orradiation. Curing or crosslinking reactions also may be carried outunder ambient conditions. Once cured, a thermosetting resin will notmelt upon the application of heat and is insoluble in solvents. Asnoted, the additional resins can also include a thermoplastic resin. Asused herein, the term “thermoplastic” refers to resins that includepolymeric components that are not joined by covalent bonds and, thereby,can undergo liquid flow upon heating.

The additional resins can be selected from, for example, (meth)acrylicpolymers, polyurethanes, polyester polymers, polyamide polymers,polyether polymers, polysiloxane polymers, epoxy resins, vinyl resins,copolymers thereof, and mixtures thereof. Thermosetting resins typicallycomprise reactive functional groups. The reactive functional groups caninclude, but are not limited to, carboxylic acid groups, amine groups,epoxide groups, alkoxy groups, hydroxyl groups, thiol groups, carbamategroups, amide groups, urea groups, isocyanate groups (including blockedisocyanate groups), and combinations thereof.

Coating compositions containing thermosetting resins are typicallyreacted with a crosslinker. As such, when additional film-forming resinsare used in the coating composition, the coating composition cancomprise additional crosslinkers that are reactive with the additionalfilm-forming resins and/or the crosslinker reactive with the polyolpolymer can also be reactive with the additional film-forming resin.Non-limiting examples of such crosslinkers include any of thecrosslinkers previously described. The thermosetting resins can alsohave functional groups that are reactive with themselves; in thismanner, such resins are self-crosslinking.

The coating compositions can also comprise a colorant. As used herein,“colorant” refers to any substance that imparts color and/or otheropacity and/or other visual effect to the composition. The colorant canbe added to the coating in any suitable form, such as discreteparticles, dispersions, solutions, and/or flakes. A single colorant or amixture of two or more colorants can be used in the coatings of thepresent invention.

Example colorants include pigments (organic or inorganic), dyes andtints, such as those used in the paint industry and/or listed in the DryColor Manufacturers Association (DCMA), as well as special effectcompositions. A colorant may include, for example, a finely dividedsolid powder that is insoluble, but wettable, under the conditions ofuse. A colorant can be organic or inorganic and can be agglomerated ornon-agglomerated. Colorants can be incorporated into the coatings by useof a grind vehicle, such as an acrylic grind vehicle, the use of whichwill be familiar to one skilled in the art.

Example pigments and/or pigment compositions include, but are notlimited to, carbazole dioxazine crude pigment, azo, monoazo, diazo,naphthol AS, benzimidazolone, isoindolinone, isoindoline and polycyclicphthalocyanine, quinacridone, perylene, perinone, diketopyrrolo pyrrole,thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavanthrone,pyranthrone, anthanthrone, dioxazine, triarylcarbonium, quinophthalonepigments, diketo pyrrolo pyrrole red (“DPPBO red”), titanium dioxide,carbon black, and mixtures thereof. The terms “pigment” and “coloredfiller” can be used interchangeably.

Example dyes include, but are not limited to, those that are solventand/or aqueous based such as phthalo green or blue, iron oxide, bismuthvanadate, anthraquinone, and perylene and quinacridone.

Example tints include, but are not limited to, pigments dispersed inwater-based or water miscible carriers such as AQUA-CHEM 896commercially available from Degussa, Inc., and CHARISMA COLORANTS andMAXITONER INDUSTRIAL COLORANTS commercially available from AccurateDispersions Division of Eastman Chemical, Inc.

Other non-limiting examples of components that can be used with thecoating compositions of the present invention include plasticizers,abrasion resistant particles, fillers including, but not limited to,micas, talc, clays, and inorganic minerals, anti-oxidants, hinderedamine light stabilizers, UV light absorbers and stabilizers,surfactants, flow and surface control agents, thixotropic agents,organic cosolvents, reactive diluents, catalysts, reaction inhibitors,additional corrosion-inhibitors, and other customary auxiliaries.

The components that form the coating composition can also be combinedand/or mixed in a liquid medium. For example, the polyol polymer,crosslinker reactive with the polyol polymer, and optional othercomponents previously described can be combined and mixed in anon-aqueous liquid medium.

After forming the coating composition of the present invention, thecomposition can be applied to a wide range of substrates known in thecoatings industry. For example, the coating composition of the presentinvention can be applied to automotive substrates and components (e.g.automotive vehicles including, but not limited to, cars, buses, trucks,trailers, etc.), industrial substrates, aircraft and aircraftcomponents, marine substrates and components such as ships, vessels, andon-shore and off-shore installations, storage tanks, windmills, nuclearplants, packaging substrates, wood flooring and furniture, apparel,electronics, including housings and circuit boards, glass andtransparencies, sports equipment, including golf balls, stadiums,buildings, bridges, and the like. These substrates can be, for example,metallic or non-metallic.

Metallic substrates include, but are not limited to, tin, steel(including electrogalvanized steel, cold rolled steel, hot-dippedgalvanized steel, steel alloys, or blasted/profiled steel, amongothers), aluminum, aluminum alloys, zinc-aluminum alloys, steel coatedwith a zinc-aluminum alloy, and aluminum plated steel. As used herein,blasted or profiled steel refers to steel that has been subjected toabrasive blasting and which involves mechanical cleaning by continuouslyimpacting the steel substrate with abrasive particles at high velocitiesusing compressed air or by centrifugal impellers. The abrasives aretypically recycled/reused materials and the process can efficientlyremoval mill scale and rust. The standard grades of cleanliness forabrasive blast cleaning is conducted in accordance with BS EN ISO8501-1.

Further, non-metallic substrates include polymeric and plasticsubstrates including polyester, polyolefin, polyamide, cellulosic,polystyrene, polyacrylic, poly(ethylene naphthalate), polypropylene,polyethylene, nylon, EVOH, polylactic acid, other “green” polymericsubstrates, poly(ethylene terephthalate) (PET), polycarbonate,polycarbonate acrylobutadiene styrene (PC/ABS), polyamide, wood, veneer,wood composite, particle board, medium density fiberboard, cement,stone, glass, paper, cardboard, textiles, leather, both synthetic andnatural, and the like. It is appreciated that the coating compositionscan be applied to various areas of any of the previously describedsubstrates to form a continuous solid coating such as over the body andedges of a substrate and which provides the superior propertiesdescribed herein.

The coating compositions of the present invention can be applied by anymeans standard in the art, such as electrocoating, spraying,electrostatic spraying, dipping, rolling, brushing, and the like. Thecoatings formed from the coating compositions of the present inventioncan be applied to a dry film thickness of 5 to 300 microns, 20 to 150microns, or 35 to 70 microns.

The coating composition can be applied to a substrate to form amonocoat. As used herein, a “monocoat” refers to a single layer coatingsystem that is free of additional coating layers. Thus, the coatingcomposition can be applied directly to a substrate without anyintermediate coating layer and cured to form a single layer coating,i.e. a monocoat. The coating composition can also be applied directlyover a pretreated substrate as a monocoat. For example, the substratecan be pretreated with an iron phosphate treatment, zinc phosphatetreatment, zirconium treatment, titanium treatment, or silane treatment.

Alternatively, the coating composition can be applied to a substrate asa first coating layer along with additional coating layers, such as asecond coating layer, to form a multi-layer coating system. It isappreciated that the multi-layer coating can comprise multiple coatinglayers such as three or more, or four or more, or five or more, coatinglayers. For example, the previously described coating composition of thepresent invention can be applied to a substrate as a primer layer andsecond and third coating layers, and, optionally, additional coatingslayers, can be applied over the primer layer as basecoats and/ortopcoats. As used herein, a “primer” refers to a coating compositionfrom which an undercoating may be deposited onto a substrate in order toprepare the surface for application of a protective or decorativecoating system. A “basecoat” refers to a coating composition from whicha coating is deposited onto a primer and/or directly onto a substrate,optionally, including components (such as pigments) that impact thecolor and/or provide other visual impact, and which may be overcoatedwith a protective and decorative topcoat.

The additional coating layers, such as a second and third coating layer,can be formed from a coating composition that includes a film-formingresin that is the same or different from the first coating layer. Theadditional coating layers can be prepared with any of the film-formingresins, crosslinkers, colorants, and/or other components previouslydescribed. Further, each coating composition can be applied as adry-on-dry process where each coating composition is dried or cured toform a coating layer prior to application of another compositioncoating. Alternatively, all or certain combinations of each coatingcomposition described herein can be applied as a wet-on-wet process anddried or cured together.

It was found that coatings formed form the coating compositions of thepresent invention comprising the polyol polymer provided improvedcorrosion resistance and good viscosity at low levels of VOC's. Thecoatings formed form the coating compositions of the present inventioncomprising the polyol polymer also provided fast property development(e.g., Konig hardness) while maintaining good appearance and improved 20degree gloss.

The following examples are presented to demonstrate the generalprinciples of the invention. The invention should not be considered aslimited to the specific examples presented. All parts and percentages inthe examples are by weight unless otherwise indicated.

EXAMPLE 1 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 1.

TABLE 1 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 1000.00Dimethylol Propionic Acid 125.36 Benzoic Acid 342.39Ethyltriphenylphosphonium iodide (ETPPI) 7.34 Triphenyl phosphite 7.34Charge 2 Butyl acetate 370.61 ¹A hydrogenated bisphenol-A epoxyfunctional resin, commercially available from Hexion SpecialtyChemicals.

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 150° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thereaction mixture was then cooled to 85° C. and Charge 2 was added to thereaction mixture. The final resin was stirred at 60° C. for 30 minutesand poured out. The weight average molecular weight of the polyesterpolyol was 994 g/mol and solids content was 80%.

The weight average molecular weight was determined by Gel PermeationChromatography using a Waters 2695 separation module with a Waters 410differential refractometer (RI detector) and polystyrene standards.Tetrahydrofuran (THF) was used as the eluent at a flow rate of 1 mlmin⁻¹, and two PL Gel Mixed C columns were used for separation.

EXAMPLE 2 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 2.

TABLE 2 Ingredients Parts by weight Charge 1 Polyester of Example 1500.00 PURALACT ® B3 lactide ² 109.03 Butyl stannoic acid 1.14 Triphenylphosphite 1.14 Charge 2 Butyl acetate 25.00 ² An intramolecular cyclicdi-ester monomer based on L-lactide, commercially available fromCORBION.

Charge 1 was added to a 1000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to70° C. and held at 70° C. for 30 minutes. Then, the reaction mixture washeated to 130° C. The reaction mixture was held at 150° C. until IRspectroscopy showed the absence of the characteristic lactide band (936cm−1) using a Thermo Scientific Nicolet iS5 FT-IR. The reaction mixturewas cooled to 85° C. and Charge 2 was added to the reaction mixture. Thefinal resin was stirred at 60° C. for 30 minutes and poured out. Theweight average molecular weight of the polyester polyol was 1328 g/moland the solids content was 80%. The weight average molecular weight wasdetermined according to Example 1.

EXAMPLE 3 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 3.

TABLE 3 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Dimethylol Propionic Acid 75.22 4-Tertbutylbenzoic Acid 299.82Ethyltriphenylphosphonium iodide (ETPPI) 4.40 Triphenyl phosphite 4.40Charge 2 Butyl acetate 240.00

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 180° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thereaction mixture was then cooled to 85° C. and Charge 2 was added toreaction mixture. The final resin was stirred at 60° C. for 30 minutesand poured out. The weight average molecular weight of the polyesterpolyol was 1053 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

EXAMPLE 4 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 4.

TABLE 4 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 400.00Dimethylol Propionic Acid 50.15 4-Tertbutylbenzoic Acid 199.88Ethyltriphenylphosphonium iodide (ETPPI) 2.94 Triphenyl phosphite 2.94Charge 2 Butyl acetate 240.00 Charge 3 PURALACT ® B3 Lactide 161.64Butyl stannoic acid 0.84 Triphenyl phosphite 0.84 Charge 4 Butyl acetate35.92

Charge 1 was added to a 2000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 183° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours).Charge 2 was added to the reaction mixture and the reaction mixture wascooled to 100° C. At 100° C., Charge 3 was added to reaction mixture.The reaction mixture was then heated to 130° C. and held at 130° C.until IR spectroscopy showed the absence of the characteristic lactideband (936 cm−1) using the Thermo Scientific Nicolet iS5 FT-IR. Then thereaction mixture was cooled to 85° C. and Charge 4 was added to thereaction mixture. The final resin was stirred at 60° C. for 30 minutesand poured out. The weight average molecular weight of the polyesterpolyol was 1380 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

EXAMPLE 5 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 5.

TABLE 5 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Benzoic Acid 136.96 Adipic acid 81.95 Ethyltriphenylphosphonium iodide(ETPPI) 4.09 Triphenyl phosphite 4.09 Charge #2 Butyl acetate 206.77

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 157° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thereaction mixture was then cooled to 85° C. and Charge 2 was added to thereaction mixture. The final resin was stirred at 60° C. for 30 minutesand poured out. The weight average molecular weight of the polyesterpolyol was 2357 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

EXAMPLE 6 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 6.

TABLE 6 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Benzoic acid 136.96 Cyclohexane dicarboxylic acid 96.55Ethyltriphenylphosphonium iodide (ETPPI) 4.09 Triphenyl phosphite 4.09Charge 2 Butyl acetate 210.46

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 177° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thereaction mixture was then cooled to 85° C. and Charge 2 was added toreaction mixture. The final resin was stirred at 60° C. for 30 minutesand poured out. The weight average molecular weight of the polyesterpolyol was 2187 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

COMPARATIVE EXAMPLE 7 Preparation of a Polyester Polyol

A polyester polyol was prepared from the components listed in Table 7.

TABLE 7 Ingredients Parts by weight Charge 1 Trimethylpentanediol 379.164-methylhexahydrophthalic anhydride 436.22 Charge 2 EPONEX ™ 1510¹600.00 Ethytriphenylphosphonium iodide (ETPPI) 0.30 Butyl acetate 342.86

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 164° C.After exotherm, the reaction mixture was held at 150° C. until the acidvalue was around 173.34 mg KOH/g as determined with a Metrohm 888Titrando using a 0.1 N KOH solution in methanol as the reagent (1˜2hours). The reaction mixture was then cooled to 100° C. and Charge 2 wasadded into the reaction mixture. Next, the reaction mixture was held at150° C. until an acid value of less than 10 mg KOH/g was obtained with aMetrohm 888 Titrando using a 0.1 N KOH solution in methanol as thereagent (˜16 hours). The reaction mixture was cooled to 60° C. andpoured out. The weight average molecular weight of the polyester polyolwas 2772 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

EXAMPLE 8 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 8.

TABLE 8 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Benzoic acid 119.84 Adipic acid 112.72 Ethyltriphenylphosphonium iodide(ETPPI) 3.90 Triphenyl phosphite 4.40 Charge 2 Butyl acetate 218.18

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 187° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thenthe reaction mixture was cooled to 85° C. and Charge 2 was added intothe reaction mixture. The final resin was stirred at 60° C. for 30minutes and poured out. The weight average molecular weight of thepolyester polyol was 4033 g/mol and the solids content was 80%. Theweight average molecular weight was determined according to Example 1.

EXAMPLE 9 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 9.

TABLE 9 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Benzoic acid 119.84 Cyclohexane dicarboxylic acid 132.77Ethyltriphenylphosphonium iodide (ETPPI) 3.90 Triphenyl phosphite 4.40Charge 2 Butyl acetate 218.18

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 192° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thenthe reaction mixture was cooled to 85° C. and Charge 2 was added intoreaction mixture. The final resin was stirred at 60 ° C. for 30 minutesand poured out. The weight average molecular weight t of the polyesterpolyol was 3245 g/mol and the solids content was 80%. The weight averagemolecular weight was determined according to Example 1.

COMPARATIVE EXAMPLE 10 Preparation of a Polyester Polyol

A polyester polyol according to the present invention was prepared fromthe components listed in Table 10.

TABLE 10 Ingredients Parts by weight Charge 1 EPONEX ™ 1510¹ 600.00Benzoic acid 119.84 Terephthalic acid 128.14 Ethyltriphenylphosphoniumiodide (ETPPI) 3.90 Triphenyl phosphite 4.40 Charge 2 Butyl acetate218.18

Charge 1 was added to a 3000 mL, 4-necked flask equipped with a motordriven stainless steel stir blade, a water-cooled condenser, a nitrogenblanket, and a heating mantle with a thermometer connected through atemperature feedback control device. The reaction mixture was heated to120° C. At 120° C., the reaction mixture was exothermal up to 168° C.After exotherm, the reaction mixture was held at 150° C. until an acidvalue of less than 0.2 mg KOH/g was obtained with a Metrohm 888 Titrandousing a 0.1 N KOH solution in methanol as the reagent (3˜4 hours). Thenthe reaction mixture was cooled to 85° C. and Charge 2 was added intothe reaction mixture. The final resin was stirred at 60° C. for 30minutes and poured out. The weight average molecular weight of thepolyester polyol was 5010 g/mol and the solids content was 80%. Theweight average molecular weight was determined according to Example 1.

After three days of storage at ambient temperature, the resin began todevelop crystallinity (haze). The polyester polyol resin thereforeshowed poor stability.

EXAMPLE 11 Polyester Polyol Properties

The polyester polyols described in Examples 1-10 were tested for variousproperties which are listed in Table 11.

TABLE 11 Viscosity ³ Mn ⁴ Mw ⁴ Example (centipoise) (g/mol) (g/mol) PDI⁵ Example 1 370 731 994 1.36 Example 2 490 923 1328 1.44 Example 3 590811 1053 1.30 Example 4 615 1018 1871 1.36 Example 5 710 1018 2357 2.31Example 6 770 945 2187 2.31 Comparative Example 7 2370 1271 2772 2.18Example 8 1370 1405 4033 2.87 Example 9 2500 1360 3245 2.39 ComparativeExample 10 4760 1416 5010 3.54 ³ Viscosity was determined at 50° C. and75 RPM using BYK Cap 2000+ high torque viscometer with Number 2 spindleand the viscosity of the resins of Examples 8-10 were determined at 50°C. and 10 RPM using BYK Cap 2000+ high torque viscometer with Number 2spindle. ⁴ Number average molecular weight (Mn) and weight averagemolecular weight (Mw) were determined by gel permeation chromatographyaccording to the description in Example 1. ⁵ Polydispersity index (PDI)is the weight average molecular weight of each resin divided by thenumber average molecular weight of the resin.

As shown in Table 11, the polyester polyol of Comparative Example 10,which had 15 weight % of an aromatic diacid (based on the total solidsweight of the reactants used to form the polyester polyol), exhibitedthe highest viscosity and considerably higher PDI than the polyesterpolyols of the present invention that were formed with aliphatic andcycloaliphatic diacids.

EXAMPLES 12-18 Preparation of Coating Compositions

Various coating compositions were prepared in three stages as describedbelow.

Part A: A milled pigment mixture was first prepared from the componentslisted in Table 12.

TABLE 12 Ex. Ex. Ex. Ex. Ex. Ex. Comp. Components 12 13 14 15 16 17 Ex.18 Polyester Example 1 37.23  — — — — — — Polyester Example 2 — 40.42  —— — — — Polyester Example 3 — — 39.65  — — — — Polyester Example 4 — — —40.28  — — — Polyester Example 5 — — — — 37.40  — — Polyester Example 6— — — — — 36.54  — Comparative Polyester — — — — — — 38.48 Example 7n-butyl acetate 9.98 9.76 10.39  10.06  9.67 9.89 9.54 Sunfast Green 7 ⁶0.78 0.77 0.78 0.77 0.75 0.76 0.73 Mapico Yellow 1050A⁷ 5.20 5.17 5.185.13 4.99 5.08 4.87 R-960-38 TiO2 ⁸ 0.69 0.69 0.69 0.68 0.67 0.68 0.65Monolite Green 860 ⁹ 0.49 0.49 0.49 0.48 0.47 0.48 0.46 Hostaperm YellowH3G ¹⁰ 1.58 1.57 1.57 1.56 1.51 1.54 1.48 Heucophos ZP-10 ¹¹ 2.92 2.902.90 2.88 2.79 2.84 2.73 Disperbyk ®-163 ¹² 0.88 0.87 0.88 0.87 0.840.86 0.82 ⁶ Green phthalocyanine organic pigment, commercially availablefrom Sun Chemical. ⁷Yellow ferric oxide hydrate inorganic pigment,commercially available from Huntsman. ⁸ Rutile titanium dioxideinorganic pigment, commercially available from The Chemours Company. ⁹Green phthalocyanine organic pigment, commercially available fromHeubach. ¹⁰ Yellow benzimidazolone organic pigment, commerciallyavailable from Clariant. ¹¹ Zinc phosphate inorganic pigment,commercially available from Heubach. ¹² Wetting and dispersing additive,commercially available form BYK-Chemie GmbH.

In the first stage, the listed pigments in Table 12 were dispersed in amixture comprising the corresponding polyester polyol, dispersants, andsolvents to form a pre-mill mixture. The pre-mill mixture was thenmilled with a Lau 200 Disperser for 120 minutes and demonstrated aHegman value of greater than 7, as determined by ASTM D1210-05.

Part B: The milled pigment mixtures were then agitated and letdown withthe additional components listed in Table 13.

TABLE 13 Ex. Ex. Ex. Ex. Ex. Ex. Comp. Components 12 13 14 15 16 17 Ex.18 n-butyl acetate 5.44 6.18 5.42 6.52 9.31 7.59 10.92 Flow additive¹³0.58 0.58 0.58 0.57 0.56 0.57 0.54 BYK-3455 ¹⁴ 0.17 0.17 0.17 0.17 0.170.17 0.16 Tinuvin ® 292 ¹⁵ 1.17 1.16 1.16 1.15 1.12 1.14 1.09 Tinuvin ®1130 ¹⁶ 0.58 0.58 0.58 0.58 0.56 0.57 0.55 Dibutyltin dilaurate 0.030.03 0.03 0.03 0.03 0.03 0.03 ¹³Acrylic based flow additive,commercially available from BASF. ¹⁴ Wetting and leveling additive,commercially available form BYK-Chemie GmbH. ¹⁵ Hindered amine lightstabilizer, commercially available from BASF. ¹⁶ UVA light stabilizer,commercially available from BASF.

Part C: Next, a polyisocyanate was added as listed in Table 14.

TABLE 14 Ex. Ex. Ex. Ex. Ex. Ex. Comparative Components 12 13 14 15 1617 Ex. 18 GXH-1080 ¹⁷ 32.27 28.65 29.54 28.28 29.18 31.28 26.95 ¹⁷Solvated polyisocyanate, commercially available from PPG.

EXAMPLE 19 Preparation and Evaluation of Coatings

Each of the coatings composition of Examples 12-18 were sprayed between65-80 microns of a dry-film thickness over an iron phosphate pretreatedcold rolled steel with a deionized water rinse treatment and anon-chrome phosphate free rinse treatment. The coatings were flashed for10 minutes at ambient temperature and humidity conditions, then baked at60° C. for 20 minutes. The coating properties of each formed coating arelisted in Table 15.

TABLE 15 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Comp. Ex. 18Viscosity Stage 80 80 85 80 78 83 83 1 + 2 (cP) ¹⁸ % Volume Solids ¹⁹61.29 60.65 61.36 60.2 58.12 59.54 56.93 V.O.C. ²⁰ 2.84 2.89 2.83 2.93.07 2.97 3.16 20° Gloss ²¹ 86.3 84.5 85.5 86.3 85.6 86.4 84.9Appearance/Popping ²² Good/Low Very Good/ Very Good/ Best/None Good/NoneGood/None Good/None Very Low Very Low Konig @ 2 hour. 68 71 75 75 44 27N/A (tacky) (sec.) ²³ Konig @ 24 hour. 149 146 145 147 135 115 87 (sec.)²³ 20 Deg. Gloss after 64.7 73.4 71.6 75.9 66.3 70.6 44.8 4000 hrs. ²⁴Scraped Scribe 6.92 8.25 8.36 7.98 6.70 9.17 10.19 Creep (mm) after 360hrs. ²⁵ ¹⁸ Viscosity at 23° C. was determined using a BYK Cap 2000+ hightorque viscometer with a Number 2 spindle at 750 RPM. ¹⁹ Volume ofnon-volatile matter measured in accordance with ASTM D2697-03(2014). ²⁰Amount of volatile organic compounds measured in accordance with ASTMD3960-05(2018). ²¹ Specular gloss measured in accordance with ASTMD523-14(2018). ²² Visual rating of relative coating smoothness anddensity of solvent pops on a 4 × 12 sq. inch coating sample. ²³ Konigmethod of pendulum hardness measuring dampening from 6 to 3 degreesaccording to ASTM D4366-95. ²⁴ Gloss of a coating after exposure toaccelerated weathering conditions measured in accordance with SAE J2527.²⁵ Corrosion resistance of a coating measured in accordance with ASTMB117-16 and ASTM D1654-08(2016)e1.

As shown in Table 15, the liquid coatings containing the polyesterpolyols of the present invention demonstrated good viscosity at lowlevels of VOC's as compared to Comparative Example 18. The liquidcoatings containing the polyester polyols of the present invention alsodemonstrated faster early property development (2 and 24 hr. Konighardness) while maintaining good appearance and improved 20 degree glossretention after 4000 hrs. of accelerated weathering as compared toComparative Example 18. The liquid coatings containing the polyesterpolyols of the present invention further exhibited improved corrosionsresistance as compared to Comparative Example 18.

The present invention is also directed to the following clauses.

Clause 1: A polyol polymer obtained from reactants comprising: a) anon-aromatic epoxy functional compound that comprises at least 30 weight% of the total solids weight of the reactants; and b) an aromaticmono-carboxylic acid functional compound, or anhydride thereof, that issubstantially free of non-aromatic ethylenic unsaturation, wherein thepolyol polymer comprises ester linkages and hydroxyl functional groups,and wherein, if the reactants further comprise an aromaticpolycarboxylic acid, the aromatic polycarboxylic acid comprises lessthan 15 weight % of the total solids weight of the reactants.

Clause 2: The polymer of clause 1, wherein the non-aromatic epoxyfunctional compound comprises a cycloaliphatic diglycidyl ether, acycloaliphatic diglycidyl ester, a cycloaliphatic epoxide, or anycombination thereof.

Clause 3: The polymer of clause 1, wherein the non-aromatic epoxyfunctional compound comprises a hydrogenated bisphenol polyepoxide or apolyepoxide derived from a hydrogenated bisphenol compound.

Clause 4: The polymer of any one of clauses 1-3, wherein thenon-aromatic epoxy functional compound comprises at least 40 weight % ofthe total solids weight of the reactants.

Clause 5: The polymer of any one of clauses 1-4, wherein the reactantsfurther comprise a non-aromatic mono-carboxylic acid.

Clause 6: The polymer of clause 5, wherein the non-aromaticmono-carboxylic acid further comprises a hydroxyl group.

Clause 7: The polymer of any one of clauses 1-6, wherein the reactantsfurther comprise a non-aromatic polycarboxylic acid.

Clause 8: The polymer of any one of clauses 1-7, wherein the reactantsfurther comprise an intramolecular cyclic ester.

Clause 9: The polymer of any one of clauses 1-8, wherein the polyolpolymer has a polydispersity index of 3.50 or less.

Clause 10: The polymer of any one of clauses 1-9, wherein the polyolpolymer has a hydroxyl value of at least 50 mg KOH/g.

Clause 11: The polymer of any one of clauses 1-10, wherein the polyolpolymer comprises carboxylic acid functional groups and epoxy functionalgroups, and has an epoxy-to-acid ratio of greater than 0.95.

Clause 12: A coating composition comprising: i) a polyol polymeraccording to any one of clauses 1-11; and ii) a crosslinker reactivewith the polyol polymer.

Clause 13: The coating composition of clause 12, wherein the crosslinkercomprises a polyisocyanate, aminoplast, or a combination thereof

Clause 14: The coating composition of clauses 12 or 13, furthercomprising a non-aqueous solvent.

Clause 15: The coating composition of any one of clauses 12-14, furthercomprising a colorant.

Clause 16: A substrate at least partially coated with a coating formedfrom the composition of any one of clauses 12-15.

Clause 17: The substrate of clause 16, wherein the coating is formeddirectly over a surface of the substrate.

Clause 18: A method of forming a polyol polymer comprising: a) reactingreactants comprising: i) a non-aromatic epoxy functional compound thatcomprises at least 30 weight % of the total solids weight of thereactants; and ii) an aromatic mono-carboxylic acid functional compound,or anhydride thereof, that is substantially free of non-aromaticethylenic unsaturation, wherein the polyol polymer comprises esterlinkages and hydroxyl functional groups, and wherein, if the reactantsfurther comprise an aromatic polycarboxylic acid, the aromaticpolycarboxylic acid comprises less than 15 weight % of the total solidsweight of the reactants.

Clause 19: The method of clause 18, wherein the polyol polymer is apolyol polymer as described in any one of clauses 1-11.

Clause 20: The method of clauses 18 or 19, wherein the reactants of stepa) further comprise a non-aromatic mono-carboxylic acid, a non-aromaticpolycarboxylic acid, or a combination thereof.

Clause 21: The method of any one of clauses 18-20, further comprising b)reacting a reaction product from step a) with an intramolecular cyclicester.

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentinvention may be made without departing from the invention as defined inthe appended claims.

The invention claimed is:
 1. A polyol polymer obtained from reactantscomprising: a) a non-aromatic epoxy functional compound that comprisesat least 30 weight % of the total solids weight of the reactants; and b)an aromatic mono-carboxylic acid functional compound, or anhydridethereof, that is substantially free of non-aromatic ethylenicunsaturation, wherein the polyol polymer comprises ester linkages andhydroxyl functional groups, and wherein, if the reactants furthercomprise an aromatic polycarboxylic acid, the aromatic polycarboxylicacid comprises less than 15 weight % of the total solids weight of thereactants.
 2. The polymer of claim 1, wherein the non-aromatic epoxyfunctional compound comprises a cycloaliphatic diglycidyl ether, acycloaliphatic diglycidyl ester, a cycloaliphatic epoxide, or anycombination thereof.
 3. The polymer of claim 1, wherein the non-aromaticepoxy functional compound comprises a hydrogenated bisphenol polyepoxideor a polyepoxide derived from a hydrogenated bisphenol compound.
 4. Thepolymer of claim 1, wherein the non-aromatic epoxy functional compoundcomprises at least 40 weight % of the total solids weight of thereactants.
 5. The polymer of claim 1, wherein the reactants furthercomprise a non-aromatic mono-carboxylic acid.
 6. The polymer of claim 5,wherein the non-aromatic mono-carboxylic acid further comprises ahydroxyl group.
 7. The polymer of claim 1, wherein the reactants furthercomprise a non-aromatic polycarboxylic acid.
 8. The polymer of claim 1,wherein the reactants further comprise an intramolecular cyclic ester.9. The polymer of claim 1, wherein the polyol polymer has apolydispersity index of 3.50 or less.
 10. The polymer of claim 1,wherein the polyol polymer has a hydroxyl value of at least 50 mg KOH/g.11. The polymer of claim 1, wherein the polyol polymer comprisescarboxylic acid functional groups and epoxy functional groups, and hasan epoxy-to-acid ratio of greater than 0.95.
 12. A coating compositioncomprising: i) a polyol polymer according to claim 1; and ii) acrosslinker reactive with the polyol polymer.
 13. The coatingcomposition of claim 12, wherein the crosslinker comprises apolyisocyanate, aminoplast, or a combination thereof
 14. The coatingcomposition of claim 12, further comprising a non-aqueous solvent. 15.The coating composition of claim 12, further comprising a colorant. 16.The coating composition of claim 12, wherein the reactants that form thepolyol polymer further comprise a non-aromatic mono-carboxylic acid. 17.The coating composition of claim 12, wherein the reactants that form thepolyol polymer further comprise a non-aromatic polycarboxylic acid. 18.The coating composition of claim 12, wherein the reactants that form thepolyol polymer further comprise an intramolecular cyclic ester.
 19. Asubstrate at least partially coated with a coating formed from thecomposition of claim
 12. 20. The substrate of claim 19, wherein thecoating is formed directly over a surface of the substrate.
 21. A methodof forming a polyol polymer comprising: a) reacting reactantscomprising: i) a non-aromatic epoxy functional compound that comprisesat least 30 weight % of the total solids weight of the reactants; andii) an aromatic mono-carboxylic acid functional compound, or anhydridethereof, that is substantially free of non-aromatic ethylenicunsaturation, wherein the polyol polymer comprises ester linkages andhydroxyl functional groups, and wherein, if the reactants furthercomprise an aromatic polycarboxylic acid, the aromatic polycarboxylicacid comprises less than 15 weight % of the total solids weight of thereactants.
 22. The method of claim 21, wherein the reactants of step a)further comprise a non-aromatic mono-carboxylic acid, a non-aromaticpolycarboxylic acid, or a combination thereof
 23. The method of claim21, further comprising b) reacting a reaction product from step a) withan intramolecular cyclic ester.